Many semi-automatic handguns employ a short recoil action to feed a fresh cartridge into the chamber after firing. During the short recoil action the barrel and slide travel rearward a short distance together in a locked position until a mechanism causes the barrel to tilt downward. At this point the tilting barrel disengages from the slide which continues traveling rearward until it extracts the fired cartridge case and feeds a new cartridge into the chamber. A spring force causes the slide to return forward, the barrel to tilt up and reengage with the slide, and the locked barrel and slide to return to their original position. Thus, the firearm automatically reloads the chamber after firing such that the operator need only pull the trigger to fire a subsequent shot.
However, if a silencer or other muzzle device is attached to the front end of the barrel, the added weight can prevent the barrel from tilting downward after the initial small movement of the locked barrel and slide. Accordingly, if the barrel is unable to disengage from the slide, the slide is prevented from following its normal rearward path and recharging the chamber. Thus, the firearm will jam.
A booster system can be used to overcome the problem of the added weight on the front end of the barrel so that the barrel can tilt normally and allow the correct short recoil action. Fundamentally, the booster adds a spring between the weight of the silencer and the barrel of the firearm so that the barrel can tilt down normally and disengage with the slide. Aside from the term “booster” these types of systems are also referred to as, recoil regulators. Most booster systems include a piston that is slidably disposed in a piston housing such that the piston and piston housing can move with respect to another relative to the length of the barrel or silencer casing. For simplicity, any axis set forth in the following description will be with respect to the trajectory of a bullet or projectile fired by the firearm, unless otherwise indicated. Thus, the piston and piston housing of a booster system have relative movement along their respective axes. Typically, the piston is fixedly attached to the barrel of the firearm, while the piston housing is fixedly attached to the bulk of the silencer. Accordingly, the booster system allows relative movement between the barrel and the silencer based on the relative movement of the piston and piston housing.
To hold the silencer in its desired position with respect to the barrel of the firearm, a booster system typically includes a spring that biases the piston forward with respect to the piston housing. After firing, the barrel and piston begin to recoil backward while the expanding gases force the piston housing and silencer forward. As a result, the spring is compressed and the inertia of the piston housing and silencer “float” with respect to the piston and barrel. The “floating” condition of the piston housing and silencer allows the barrel to move backward, tilt down and disengage from the slide so that the chamber is recharged with a fresh cartridge. The spring of the booster system then ensures that the system is restored to its original position as it expands back to its former length.
Although booster systems help firearms with suppressors and short recoil actions fire reliably, they add to the overall length of the combined handgun and suppressor. The added length is typically seen as undesirable. Thus, booster systems with shorter lengths are highly advantageous.